Method for producing a printing stencil for technical printing for applying a printed pattern to a substrate and printing stencil for technical printing

Abstract

Disclosed is a method for producing a printing stencil for technical printing for applying a printed pattern to a substrate and to a printing stencil. The method includes supplying a carrier layer, supplying a structure layer, said layer being located beneath the carrier layer, making an elongate printed image opening, corresponding to at least part of the printed pattern, in the structure layer, and making carrier layer openings in the region of the printed image opening. The method uses a laser device designed to emit a laser beam in pulses, and includes making a row of carrier layer openings, extending in the longitudinal direction of the printed image opening, wherein, for making a carrier layer opening, a focusing apparatus is positioned near the carrier layer opening, and the carrier layer opening is by means of one or several laser pulses, and the focusing apparatus of the laser device.

The invention claimed is: 
     
       1. A method for producing a printing stencil for applying a printed pattern on a substrate, comprising:
 supplying a carrier layer for the printing stencil, the carrier layer comprising metal, 
 supplying a structure layer for the printing stencil, said layer being located beneath the carrier layer, 
 making a printed image opening, which extends in the longitudinal direction and corresponds to at least part of the printed pattern, in the structure layer, and 
 making carrier layer openings in the carrier layer in the region of the printed image opening by means of a laser beam defocussed depending on the width of the carrier layer opening to be made so as to apply a printing medium to the substrate through the carrier layer openings and the printed image opening. 
 
     
     
       2. The method according to  claim 1 , wherein
 a laser device is used for making the carrier layer openings, said laser device comprising a focusing apparatus and being designed to emit the laser beam in laser pulses and adjust the laser beam by means of the focusing apparatus so as to defocus the laser beam at the height of the surface of the carrier layer depending on the width of the carrier layer openings to be made. 
 
     
     
       3. The method according to  claim 1 , wherein
 the laser beam is defocused in such a way that the width of the cross-section of the laser beam at the height of the surface of the carrier layer is approximately 50% to 95% the width of the carrier layer openings to be made by means of one or several laser pulses. 
 
     
     
       4. The method according to  claim 1 , wherein
 a task of making the carrier layer openings comprises making a row of carrier layer openings, extending in the longitudinal direction of the printed image opening, and 
 the position of the laser beam is moved after making a carrier layer opening between two successive laser pulses relative to the carrier layer and in the longitudinal direction of the printed image opening to a position of the carrier layer opening to be subsequently made. 
 
     
     
       5. The method according to  claim 4 , wherein
 for making a respective carrier layer opening of the row, the position of the laser beam is positioned at a position of the respective carrier layer opening and the respective carrier layer opening is made by means of one or several laser pulses at this position. 
 
     
     
       6. The method according to  claim 5 , wherein
 the position of the laser beam is not moved substantially while making the respective carrier layer opening by means of one or several laser pulses. 
 
     
     
       7. The method according to  claim 4 , wherein
 for making a respective carrier layer opening of the row, the position of the laser beam is positioned at a first position of the respective carrier layer opening and the respective carrier layer opening is made by means of a laser pulse by moving the position of the laser beam during one laser pulse from the first position to a second position of the respective carrier layer opening. 
 
     
     
       8. The method according to  claim 7 , wherein
 the position of the laser beam is moved during one laser pulse from the first position to the second position of the respective carrier layer opening in the longitudinal direction of the printed image opening. 
 
     
     
       9. The method according to  claim 7 , wherein
 a feed rate in the movement of the position of the laser beam relative to the carrier layer from the first position to the second position of the carrier layer opening to be made and/or the pulse duration of the laser pulse of the laser beam are chosen depending on the length of the carrier layer opening to be made. 
 
     
     
       10. The method according to  claim 1 , further comprising
 adjusting a shape and/or size of the cross-section of the defocused laser beam at the height of the surface of the carrier layer by means of a focusing apparatus of the laser device. 
 
     
     
       11. The method according to  claim 10 , wherein
 the width of the cross-section of the defocused laser beam at the height of the surface of the carrier layer is adjusted transversely to the longitudinal direction of the printed image opening depending on the width of the printed image opening. 
 
     
     
       12. The method according to  claim 10 , wherein
 the laser beam is defocused so as to have a substantially circular cross-section at the height of the surface of the carrier layer. 
 
     
     
       13. The method according to  claim 10 , wherein
 the laser beam is defocused to as to have a substantially elliptic cross-section at the height of the surface of the carrier layer. 
 
     
     
       14. The method according to  claim 13 , wherein
 the elliptic main axis of the laser cross-section is aligned transversely, in particular perpendicularly, to the longitudinal direction of the printed image opening. 
 
     
     
       15. The method according to  claim 1 , further comprising
 adjusting one or several of the parameters frequency or period of the pulsed laser beam, pulse duration of the laser pulses, duty cycle of the pulsed laser beam, on/off ratio of the pulsed laser beam. 
 
     
     
       16. The method according to  claim 1 , wherein
 a web is formed in the carrier layer when the position of the laser beam is moved relative to the carrier layer between two successive laser pulses between two adjacent carrier layer openings of the row of carrier layer openings. 
 
     
     
       17. The method according to  claim 16 , wherein
 a feed rate in the movement of the position of the laser beam relative to the carrier layer from a position of a carrier layer opening made to a position of a carrier layer opening to be made is chosen depending on a predetermined web width. 
 
     
     
       18. The method according to  claim 17 , wherein
 the feed rate in the movement of the position of the laser beam relative to the carrier layer from a position of a carrier layer opening made to a position of a carrier layer opening to be subsequently made is additionally chosen depending on the width of the carrier layer openings in the longitudinal direction of the printed image opening. 
 
     
     
       19. The method according to  claim 18 , wherein
 the feed rate in the movement of the laser beam relative to the carrier layer from the position of a carrier layer opening made to the position of a carrier layer opening to be subsequently made is chosen to be smaller or substantially equal (BL+SB)/(T−τ), wherein BL designates the width of the carrier layer openings in the longitudinal direction of the printed image opening, SB designates the predetermined web width, T is the period of the pulsed laser beam and τ is the pulse duration of the laser pulses. 
 
     
     
       20. The method according to  claim 1 , wherein
 a focusing apparatus of the laser device and/or the carrier layer is moved when the position of the laser beam is moved relative to the carrier layer. 
 
     
     
       21. The method according to  claim 4 , wherein
 the task of making the carrier layer openings comprises making at least one further second row of carrier layer openings, extending in the longitudinal direction of the printed image opening and parallel to the first row of carrier layer openings. 
 
     
     
       22. The method according to  claim 21 , wherein
 in each case a carrier layer opening of the first row is overlaid with a carrier layer opening of the at least one further second row in such a way that each carrier layer opening is formed in the produced printing stencil from two or more carrier layer openings of the at least two rows, wherein a web is formed between carrier layer openings adjacent in the longitudinal direction of the printed image opening. 
 
     
     
       23. A printing stencil for applying a printed pattern to a substrate, which is produced according to a method of  claim 1 , comprising:
 a carrier layer for the printing stencil, the carrier layer comprising, metal, 
 a structure layer for the printing stencil, said layer being located beneath the carrier layer, 
 wherein the structure layer has an elongate printed image opening, corresponding to at least part of the printed pattern, in the structure layer, and 
 wherein in the region of the printed image opening the carrier layer comprises one or several rows of carrier layer openings, extending in the longitudinal direction of the printed image opening. 
 
     
     
       24. The printing stencil according to  claim 23 , wherein
 the carrier layer openings of a row are formed in a substantially circular fashion. 
 
     
     
       25. The printing stencil according to  claim 23 , wherein
 the carrier layer openings of a row are formed in a substantially elliptic fashion. 
 
     
     
       26. The printing stencil according to  claim 25 , wherein
 the elliptic main axis of the carrier layer openings of a row are aligned transversely, in particular perpendicularly, to the longitudinal direction of the printed image opening. 
 
     
     
       27. The printing stencil according to  claim 23 , wherein
 the carrier layer openings of a row have substantially the shape of an oblong hole. 
 
     
     
       28. The printing stencil according to  claim 23 , wherein
 the carrier layer has precisely one row of carrier layer openings, extending in the longitudinal direction of the printed image opening, in the region of the printed image opening, wherein a respective web is formed between adjacent carrier layer openings, said web being partially molten on the structure layer side and being thus reduced in height compared to the thickness of the carrier layer. 
 
     
     
       29. The printing stencil according to  claim 23 , wherein in each case a carrier layer opening of a first row is overlaid with a carrier layer opening of at least one further second row in such a way that each carrier layer opening is formed in the printing stencil from two or more carrier layer openings of the at least two rows, wherein a respective web is formed between carrier layer openings adjacent in the longitudinal direction of the printed image opening.